1. Field of the Invention
The present invention relates to test circuits on-board integrated circuit chips. More particularly, the present invention relates to test circuits having an input which overrides all flip-flop or latch inputs such that data into the chip becomes data out, thus, converting the flip-flop or latch into a non-inverting buffer.
2. Description of the Prior Art
Heretofore, scan set latch circuits were known and used on-board integrated circuit chips to implement series scan test patterns. Such prior art scan set latch circuits are known to require sequentially clocking of a pattern into the series string of latches to obtain test patterns out. Such series scan test circuits when tested on a chip using scan set latch circuits requires a complex setup as well as three or more dedicated pins on the chip in addition to a clock input pin.
It would be desirable to simplify the prior art scan set test circuits and procedure without requiring any significant on-board chip circuitry.